Decades of Work End in Major Antimatter Discovery

Earth and all the other planets are made of matter—and at the time of the Big Bang, matter and its opposite, antimatter, were created in equal amounts. In our current world, antimatter is all but impossible to find, making a big discovery regarding it equally big news. The finding is that, like matter, antimatter falls in response to gravity. The BBC explains why that determination—one predicted by Albert Einstein—well, matters: "During the Big Bang, matter and antimatter should have combined and cancelled each other, leaving nothing but light. Why they didn't is one of physics' great mysteries and uncovering differences between the two is the key to solving it."

In the first few moments after the Big Bang, matter somehow got the upper hand, and some scientists have speculated that their respective relationships to gravity might be the linchpin. What they don't yet know is whether antimatter falls at the same rate as matter. The study, published in Nature, was conducted at the CERN lab in Switzerland, where over decades of work, scientists have produce antiprotons and positrons that are directed into a giant magnet, where they combine to form thousands of atoms of antihydrogen, the antimatter counterpart to hydrogen, the simplest atom. The magnet creates a field that traps the antihydrogen; when that field is shut off, the freed antihydrogen atoms do what they will—and as sensors determined, they fell down, not up.

"It has taken us 30 years to learn how to make this anti-atom, to hold on to it, and to control it well enough that we could actually drop it in a way that it would be sensitive to the force of gravity," said Jeffrey Hangst, the spokesperson for the Antihydrogen Laser Physics Apparatus collaboration at CERN, per the Guardian. "The next step is to measure the acceleration as precisely as we can." An accompanying article in Nature notes the finding isn't exactly surprising, as "a difference in the gravitational behavior of matter and antimatter would have huge implications for physics." But as a University of Florida physics professor puts it, "It really is a cool result." (More antimatter stories.)